That ("They are listening, filming and tracking every single thing you do near that device") is a claim you're going to have to substantiate. Don't spread such rumours unless you can back them up.
He's not suggesting they are tracking you through their ad network as you go to websites that use them.
He's suggesting they are secretly filming you, logging your keystrokes, and rerouting your mic audio. That is a very bold claim that should be backed up or retracted.
If the claim being made was that they track your usage of their products, that would have been a reasonable response. But the claim being made is that they continuously monitor you through the webcam and microphone. That is extremely bold and, may I say, complete tinfoil nuttery.
Why is that so hard to believe? Personalized ads are huge right now, if you could listen in to people's conversations you can use the data to improve your ad conversion rate. If there's ROI in recording and doing the data collection you can bet they have at least experimented with it.
Can't imagine what recording webcams would do- but I suppose it might be effective for something.